GQUEUE
From uGFX Wiki
The GQUEUE modules does provide queues and buffers.
Buffers
A pool of buffers can be allocated using gfxBufferAlloc(num, size)
where num is the number of buffers and size the size per buffer. The created buffer pool is global. It is not possible to have more than one buffer pool.
Memory once dedicated to be come a buffer cannot be freed anymore. Therefore, the amount and size of the buffers allocated should be chosen carefully.
Queues
Although the queues provided by the GQUEUE module are mainly used internally, these features are still accessible for the user.